I am new to this forum and new to ar platform so be please excuse rookie questions.
I purchased 308 ar from a local shop, it has an Anderson Manufacturing AM-10 lower but I don't know how to tell what the upper is. The only stamping I can find on the upper is a keyhole symbol on the right rear side. It doesn't have a dust cover for the ejection port and it doesn't have a forward assist.
I believe it to be an assembled rifle and not one purchased complete but I don't know this for sure, I have attached a picture of the upper receiver.
One of the reasons I want to know is that I would like to change the barrel and want to make sure what I buy will fit.
Thanks
